<template>
    <admin-layout>
        <contextmenu :itemList="menuItemList" :visible.sync="menuVisible" @select="onMenuSelect"/>
        <tabs-head
            v-if="multiPage"
            :active="activePage"
            :page-list="pageList"
            @change="changePage"
            @close="remove"
            @refresh="refresh"
            @contextmenu="onContextmenu"
        />
        <div :class="['tabs-view-content', layout, pageWidth]" :style="`margin-top: ${multiPage ? -24 : 0}px`">
            <page-toggle-transition :disabled="animate.disabled" :animate="animate.name" :direction="animate.direction">
                <a-keep-alive :exclude-keys="excludeKeys" v-if="multiPage && cachePage" v-model="clearCaches">
                    <router-view v-if="!refreshing" ref="tabContent" :key="$route.path"/>
                </a-keep-alive>
                <router-view ref="tabContent" v-else-if="!refreshing"/>
            </page-toggle-transition>
        </div>
    </admin-layout>
</template>

<script>
import AdminLayout from '@/layouts/AdminLayout'
import Contextmenu from '@/components/menu/Contextmenu'
import PageToggleTransition from '@/components/transition/PageToggleTransition'
import {mapState, mapMutations} from 'vuex'
import {getI18nKey} from '@/utils/routerUtil'
import AKeepAlive from '@/components/cache/AKeepAlive'
import TabsHead from '@/layouts/tabs/TabsHead'

export default {
    name: 'TabsView',
    i18n: require('./i18n'),
    components: {TabsHead, PageToggleTransition, Contextmenu, AdminLayout, AKeepAlive},
    data() {
        return {
            clearCaches: [],
            pageList: [],
            activePage: '',
            menuVisible: false,
            refreshing: false,
            excludeKeys: []
        }
    },
    computed: {
        ...mapState('setting', ['multiPage', 'cachePage', 'animate', 'layout', 'pageWidth']),
        menuItemList() {
            return [
                {key: '1', icon: 'vertical-right', text: this.$t('closeLeft')},
                {key: '2', icon: 'vertical-left', text: this.$t('closeRight')},
                {key: '3', icon: 'close', text: this.$t('closeOthers')},
                {key: '4', icon: 'sync', text: this.$t('refresh')},
            ]
        },
        tabsOffset() {
            return this.multiPage ? 24 : 0
        }
    },
    created() {
        this.loadCacheConfig(this.$router?.options?.routes)
        this.loadCachedTabs()
        const route = this.$route
        if (this.pageList.findIndex(item => item.path === route.path) === -1) {
            this.pageList.push(this.createPage(route))
        }
        this.activePage = route.path
        if (this.multiPage) {
            this.$nextTick(() => {
                this.setCachedKey(route)
            })
            this.addListener()
        }
    },
    mounted() {
        this.correctPageMinHeight(-this.tabsOffset)
    },
    beforeDestroy() {
        this.removeListener()
        this.correctPageMinHeight(this.tabsOffset)
    },
    watch: {
        '$router.options.routes': function (val) {
            this.excludeKeys = []
            this.loadCacheConfig(val)
        },
        '$route': function (newRoute) {
            this.activePage = newRoute.path
            const page = this.pageList.find(item => item.path === newRoute.path)
            if (!this.multiPage) {
                this.pageList = [this.createPage(newRoute)]
            } else if (page) {
                page.fullPath = newRoute.fullPath
            } else if (!page) {
                this.pageList.push(this.createPage(newRoute))
            }
            if (this.multiPage) {
                this.$nextTick(() => {
                    this.setCachedKey(newRoute)
                })
            }
        },
        'multiPage': function (newVal) {
            if (!newVal) {
                this.pageList = [this.createPage(this.$route)]
                this.removeListener()
            } else {
                this.addListener()
            }
        },
        tabsOffset(newVal, oldVal) {
            this.correctPageMinHeight(oldVal - newVal)
        }
    },
    methods: {
        changePage(key) {
            this.activePage = key
            const page = this.pageList.find(item => item.path === key)
            this.$router.push(page.fullPath)
        },
        remove(key, next) {
            if (this.pageList.length === 1) {
                return this.$message.warning(this.$t('warn'))
            }
            //清除缓存
            let index = this.pageList.findIndex(item => item.path === key)
            this.clearCaches = this.pageList.splice(index, 1).map(page => page.cachedKey)
            if (next) {
                this.$router.push(next)
            } else if (key === this.activePage) {
                index = index >= this.pageList.length ? this.pageList.length - 1 : index
                this.activePage = this.pageList[index].path
                this.$router.push(this.activePage)
            }
        },
        refresh(key, page) {
            page = page || this.pageList.find(item => item.path === key)
            page.loading = true
            this.clearCache(page)
            if (key === this.activePage) {
                this.reloadContent(() => page.loading = false)
            } else {
                // 其实刷新很快，加这个延迟纯粹为了 loading 状态多展示一会儿，让用户感知刷新这一过程
                setTimeout(() => page.loading = false, 500)
            }
        },
        onContextmenu(pageKey, e) {
            if (pageKey) {
                e.preventDefault()
                e.meta = pageKey
                this.menuVisible = true
            }
        },
        onMenuSelect(key, target, pageKey) {
            switch (key) {
                case '1':
                    this.closeLeft(pageKey);
                    break
                case '2':
                    this.closeRight(pageKey);
                    break
                case '3':
                    this.closeOthers(pageKey);
                    break
                case '4':
                    this.refresh(pageKey);
                    break
                default:
                    break
            }
        },
        closeOthers(pageKey) {
            // 清除缓存
            const clearPages = this.pageList.filter(item => item.path !== pageKey && !item.unclose)
            this.clearCaches = clearPages.map(item => item.cachedKey)
            this.pageList = this.pageList.filter(item => !clearPages.includes(item))
            // 判断跳转
            if (this.activePage != pageKey) {
                this.activePage = pageKey
                this.$router.push(this.activePage)
            }
        },
        closeLeft(pageKey) {
            const index = this.pageList.findIndex(item => item.path === pageKey)
            // 清除缓存
            const clearPages = this.pageList.filter((item, i) => i < index && !item.unclose)
            this.clearCaches = clearPages.map(item => item.cachedKey)
            this.pageList = this.pageList.filter(item => !clearPages.includes(item))
            // 判断跳转
            if (!this.pageList.find(item => item.path === this.activePage)) {
                this.activePage = pageKey
                this.$router.push(this.activePage)
            }
        },
        closeRight(pageKey) {
            // 清除缓存
            const index = this.pageList.findIndex(item => item.path === pageKey)
            const clearPages = this.pageList.filter((item, i) => i > index && !item.unclose)
            this.clearCaches = clearPages.map(item => item.cachedKey)
            this.pageList = this.pageList.filter(item => !clearPages.includes(item))
            // 判断跳转
            if (!this.pageList.find(item => item.path === this.activePage)) {
                this.activePage = pageKey
                this.$router.push(this.activePage)
            }
        },
        clearCache(page) {
            page._init_ = false
            this.clearCaches = [page.cachedKey]
        },
        reloadContent(onLoaded) {
            this.refreshing = true
            setTimeout(() => {
                this.refreshing = false
                this.$nextTick(() => {
                    this.setCachedKey(this.$route)
                    if (typeof onLoaded === 'function') {
                        onLoaded.apply(this, [])
                    }
                })
            }, 200)
        },
        pageName(page) {
            return this.$t(getI18nKey(page.keyPath))
        },
        /**
         * 添加监听器
         */
        addListener() {
            window.addEventListener('page:close', this.closePageListener)
            window.addEventListener('page:refresh', this.refreshPageListener)
            window.addEventListener('unload', this.unloadListener)
        },
        /**
         * 移出监听器
         */
        removeListener() {
            window.removeEventListener('page:close', this.closePageListener)
            window.removeEventListener('page:refresh', this.refreshPageListener)
            window.removeEventListener('unload', this.unloadListener)
        },
        /**
         * 页签关闭事件监听
         * @param event 页签关闭事件
         */
        closePageListener(event) {
            const {closeRoute, nextRoute} = event.detail
            const closePath = typeof closeRoute === 'string' ? closeRoute : closeRoute.path
            const path = closePath && closePath.split('?')[0]
            this.remove(path, nextRoute)
        },
        /**
         * 页面刷新事件监听
         * @param event 页签关闭事件
         */
        refreshPageListener(event) {
            const {pageKey} = event.detail
            const path = pageKey && pageKey.split('?')[0]
            this.refresh(path)
        },
        /**
         * 页面 unload 事件监听器，添加页签到 session 缓存，用于刷新时保留页签
         */
        unloadListener() {
            const tabs = this.pageList.map(item => ({...item, _init_: false}))
            sessionStorage.setItem(process.env.VUE_APP_TBAS_KEY, JSON.stringify(tabs))
        },
        createPage(route) {
            return {
                keyPath: route.matched[route.matched.length - 1].path,
                fullPath: route.fullPath, loading: false,
                path: route.path,
                title: route.meta && route.meta.page && route.meta.page.title,
                unclose: route.meta && route.meta.page && (route.meta.page.closable === false),
            }
        },
        /**
         * 设置页面缓存的key
         * @param route 页面对应的路由
         */
        setCachedKey(route) {
            const page = this.pageList.find(item => item.path === route.path)
            page.unclose = route.meta && route.meta.page && (route.meta.page.closable === false)
            if (!page._init_) {
                const vnode = this.$refs.tabContent.$vnode
                page.cachedKey = vnode.key + vnode.componentOptions.Ctor.cid
                page._init_ = true
            }
        },
        /**
         * 加载缓存的 tabs
         */
        loadCachedTabs() {
            const cachedTabsStr = sessionStorage.getItem(process.env.VUE_APP_TBAS_KEY)
            if (cachedTabsStr) {
                try {
                    const cachedTabs = JSON.parse(cachedTabsStr)
                    if (cachedTabs.length > 0) {
                        this.pageList = cachedTabs
                    }
                } catch (e) {
                    console.warn('failed to load cached tabs, got exception:', e)
                } finally {
                    sessionStorage.removeItem(process.env.VUE_APP_TBAS_KEY)
                }
            }
        },
        loadCacheConfig(routes, pCache = true) {
            routes.forEach(item => {
                const cacheAble = item.meta?.page?.cacheAble ?? pCache ?? true
                if (!cacheAble) {
                    this.excludeKeys.push(new RegExp(`${item.path}\\d+$`))
                }
                if (item.children) {
                    this.loadCacheConfig(item.children, cacheAble)
                }
            })
        },
        ...mapMutations('setting', ['correctPageMinHeight'])
    }
}
</script>

<style scoped lang="less">
.tabs-view {
    margin: -16px auto 8px;

    &.head.fixed {
        max-width: 1400px;
    }
}

.tabs-view-content {
    position: relative;
    height: 100%;

    &.head.fixed {
        width: 1400px;
        margin: 0 auto;
    }
}
</style>
